The invention relates to a filter system for an internal combustion engine of a motor vehicle. The filter system is comprised of an unfiltered air inlet, a clean air outlet, a housing, and a filter element arranged in the housing.
German patent application 100 28 856 discloses a filter arrangement arranged underneath the engine hood. This filter arrangement has an energy absorbing structure into which structure the fresh air supply channel and the filter arrangement are spatially integrated. The energy absorbing structure is provided in order to dampen the impact of a pedestrian in case of an accident. The energy absorbing structure ensures also a reduction of the sound emission in the upward direction so that a sound proofing mat arranged at the underside of the engine hood is not needed. A disadvantage of this known arrangement is that as a result of the structure a significant proportion of the space available for the filter is lost. This space is required in order to achieve sound proofing properties like those of a Helmholtz resonator.
Great Britain patent application 2 235 283 discloses an engine hood for a passenger car. In order to not have to arrange a hood scoop for fresh air in the area of the top side of the engine hood and in order to reduce the dangers resulting from such a hood scoop in case of an accident involving a pedestrian, a fresh air supply channel including the corresponding filter arrangement is mounted on an underside of the outer skin of the engine hood. However, this provides only minimal improvement with regard to impact protection.